diff --git a/README.md b/README.md
index 00614a8..1ade192 100644
--- a/README.md
+++ b/README.md
@@ -7,7 +7,9 @@ You see an armed time bomb but don't know how to disarm it. Your friends found a
 1. [Install](https://www.arduino.cc/en/Guide/#install-the-arduino-desktop-ide) the Arduino IDE.
 2. Clone this repository with Git in a permanent location on your drive.
 3. Symlink the library: `ln -s /ABSOLUTE/PATH/TO/REPO/lib /PATH/TO/Arduino/libraries/obus`
-4. TODO
+  (on most Linux distro's, this the Arduino folder is in `$HOME/Arduino`)
+4. Follow [these steps](https://github.com/autowp/arduino-mcp2515/#software-usage) to install the CAN library
+5. Execute `./src/new_module.sh` to create a new module
 
 # Background
 ## Game
diff --git a/lib/obus_can.cpp b/lib/obus_can.cpp
index 6068597..d242019 100644
--- a/lib/obus_can.cpp
+++ b/lib/obus_can.cpp
@@ -2,9 +2,12 @@
 
 #include "obus_can.h"
 
+// Chip select for the CAN module
+#define MCP_CS 8
+
 namespace obus_can {
 
-MCP2515 mcp2515(10);
+MCP2515 mcp2515(MCP_CS);
 bool is_init = false;
 
 
@@ -136,6 +139,9 @@ bool receive(struct message *msg) {
 	return true;
 }
 
+bool is_error_condition() {
+	return mcp2515.getInterrupts() & MCP2515::CANINTF_ERRIF;
+}
 
 void send(struct message *msg) {
 	if (!is_init) {
diff --git a/lib/obus_can.h b/lib/obus_can.h
index dee7d9e..2994a9c 100644
--- a/lib/obus_can.h
+++ b/lib/obus_can.h
@@ -77,7 +77,7 @@ void init();
 /**
  * Receive a message
  *
- * @param msg Pointer to memory where the received message will be wriitten
+ * @param msg Pointer to memory where the received message will be written
  * @return true if a message was received, false otherwise
  */
 bool receive(struct message *msg);
@@ -90,6 +90,8 @@ bool receive(struct message *msg);
  */
 void send(struct message *msg);
 
+bool is_error_condition();
+
 
 /**
  * For internal use only
diff --git a/lib/obus_module.cpp b/lib/obus_module.cpp
index b3b6a21..81ce44f 100644
--- a/lib/obus_module.cpp
+++ b/lib/obus_module.cpp
@@ -1,11 +1,18 @@
 #include "obus_can.h"
 #include "obus_module.h"
 
+#define RED_LED A4
+#define GREEN_LED A5
+
+#define MCP_INT 2
+
 namespace obus_module {
 
+
 struct obus_can::module this_module;
 uint8_t strike_count;
-
+bool active;
+uint32_t time_stop_strike_led;
 
 void setup(uint8_t type, uint8_t id) {
 	this_module.type = type;
@@ -14,19 +21,83 @@ void setup(uint8_t type, uint8_t id) {
 	obus_can::init();
 
 	strike_count = 0;
+	active = false;
+	pinMode(RED_LED, OUTPUT);
+	pinMode(GREEN_LED, OUTPUT);
+	digitalWrite(RED_LED, LOW);
+	digitalWrite(GREEN_LED, LOW);
 }
 
-void loop() {
+bool loopPuzzle(obus_can::message* message) {
+	// Check if we need to turn the red "strike" LED back off after
+	//  turning it on because of a strike
+	if (time_stop_strike_led && time_stop_strike_led > millis()) {
+		digitalWrite(RED_LED, LOW);
+		time_stop_strike_led = 0;
+	}
+	// TODO this can be more efficient by only enabling error interrupts and
+	//  reacting to the interrupt instead of checking if the flag is set in a loop
+	// We will need to fork our CAN library for this, because the needed functions
+	//  are private
+	if (obus_can::is_error_condition()) {
+		bool blink = false;
+		while (true) {
+			digitalWrite(RED_LED, blink);
+			digitalWrite(GREEN_LED, blink);
+			blink = !blink;
+			delay(500);
+		}
+	}
+	if (obus_can::receive(message)) {
+		switch(message->msg_type) {
+			case OBUS_MSGTYPE_C_GAMESTART:
+				active = true;
+				callback_game_start();
+				break;
+			case OBUS_MSGTYPE_C_HELLO:
+				obus_can::send_m_hello(this_module);
+				break;
+			case OBUS_MSGTYPE_C_SOLVED:
+			case OBUS_MSGTYPE_C_TIMEOUT:
+			case OBUS_MSGTYPE_C_STRIKEOUT:
+				active = false;
+				callback_game_stop();
+				break;
+			case OBUS_MSGTYPE_C_ACK:
+				break;
+			case OBUS_MSGTYPE_C_STATE:
+				return true;
+		}
+		return false;
+	}
+}
 
+bool loopNeedy(obus_can::message* message) {
+	// For now this is the same function
+	return loopPuzzle(message);
 }
 
 void strike() {
+	if (!active) {
+		return;
+	}
 	strike_count++;
+	digitalWrite(RED_LED, HIGH);
+	time_stop_strike_led = millis() + 1000;
 	obus_can::send_m_strike(this_module, strike_count);
 }
 
 void solve() {
+	if (!active) {
+		return;
+	}
 	obus_can::send_m_solved(this_module);
+	digitalWrite(GREEN_LED, HIGH);
+	active = false;
+}
+
+bool is_active() {
+	return active;
 }
 
 }
diff --git a/lib/obus_module.h b/lib/obus_module.h
index f3ed0a3..8c585e1 100644
--- a/lib/obus_module.h
+++ b/lib/obus_module.h
@@ -8,16 +8,24 @@
 #define OBUS_NEEDY_ID_DEVELOPMENT  255
 #define OBUS_INFO_ID_DEVELOPMENT   255
 
+void callback_game_start();
+
+void callback_game_stop();
+
 namespace obus_module {
 
 void setup(uint8_t type, uint8_t id);
 
-void loop();
+bool loopPuzzle(obus_can::message* message);
+
+bool loopNeedy(obus_can::message* message);
 
 void strike();
 
 void solve();
 
+bool is_active();
+
 }
 
 #endif /* end of include guard: OBUS_MODULE_H */
diff --git a/src/modules/testmodule_buttons/doc/index.md b/src/modules/testmodule_buttons/doc/index.md
new file mode 100644
index 0000000..f751538
--- /dev/null
+++ b/src/modules/testmodule_buttons/doc/index.md
@@ -0,0 +1,6 @@
+## Testmodule buttons
+
+Don't press the red button. Press the green button to solve the module.
+
+### Credits
+Module developed by redfast00.
diff --git a/src/modules/testmodule_buttons/testmodule_buttons.ino b/src/modules/testmodule_buttons/testmodule_buttons.ino
new file mode 100644
index 0000000..501e17c
--- /dev/null
+++ b/src/modules/testmodule_buttons/testmodule_buttons.ino
@@ -0,0 +1,44 @@
+// (c) 2020, redfast00
+// See the LICENSE file for conditions for copying
+
+#include <obus_module.h>
+#include <ezButton.h>
+
+ezButton red_button(5);
+ezButton green_button(6);
+
+void setup() {
+	Serial.begin(115200);
+	// WARNING: do not use 255 for your module
+	obus_module::setup(OBUS_TYPE_PUZZLE, 255);
+	red_button.setDebounceTime(100);
+	green_button.setDebounceTime(100);
+}
+
+obus_can::message message;
+
+void loop() {
+	bool received = obus_module::loopPuzzle(&message);
+	// TODO handle update frames (not needed for this module, but could be useful as example code)
+
+	red_button.loop();
+	green_button.loop();
+
+	if (red_button.getCount() > 0) {
+		red_button.resetCount();
+		obus_module::strike();
+	}
+
+	if (green_button.getCount() > 0) {
+		green_button.resetCount();
+		obus_module::solve();
+	}
+}
+
+void callback_game_start() {
+	// Intentionally emtpy
+}
+
+void callback_game_stop() {
+	// Intentionally empty
+}
diff --git a/src/modules/testmodule_needy_buttons/doc/index.md b/src/modules/testmodule_needy_buttons/doc/index.md
new file mode 100644
index 0000000..56142da
--- /dev/null
+++ b/src/modules/testmodule_needy_buttons/doc/index.md
@@ -0,0 +1,6 @@
+## Testmodule needy buttons
+
+If the module starts making a sound, press the button.
+
+### Credits
+Module developed by redfast00.
diff --git a/src/modules/testmodule_needy_buttons/testmodule_needy_buttons.ino b/src/modules/testmodule_needy_buttons/testmodule_needy_buttons.ino
new file mode 100644
index 0000000..ab6b8df
--- /dev/null
+++ b/src/modules/testmodule_needy_buttons/testmodule_needy_buttons.ino
@@ -0,0 +1,68 @@
+// (c) 2020, redfast00
+// See the LICENSE file for conditions for copying
+
+#include <obus_module.h>
+#include <ezButton.h>
+
+#define SPEAKER_PIN 10
+
+ezButton green_button(6);
+
+void setup() {
+	Serial.begin(115200);
+	// WARNING: do not use 255 for your module
+	obus_module::setup(OBUS_TYPE_NEEDY, 255);
+	green_button.setDebounceTime(100);
+}
+
+obus_can::message message;
+
+uint32_t next_activation_time = 0;
+uint32_t trigger_time = 0;
+
+void loop() {
+	bool is_message_valid = obus_module::loopNeedy(&message);
+	green_button.loop();
+
+	// Every second, have a 1/20 chance to trigger the countdown
+	if (obus_module::is_active() && !trigger_time && (millis() > next_activation_time)) {
+		next_activation_time = millis() + 1000;
+		if (random(20) == 0) {
+			trigger_time = millis() + 30000;
+		}
+	}
+
+	// Strike if time runs out
+	if (trigger_time && millis() > trigger_time) {
+		obus_module::strike();
+		trigger_time = 0;
+	}
+
+	// If the button is pressed, reset countdown if countdown is running, else strike
+	if (green_button.getCount() > 0) {
+		green_button.resetCount();
+		if (trigger_time) {
+			trigger_time = 0;
+		} else {
+			obus_module::strike();
+		}
+	}
+
+	// Play the appropriate sound
+	if (trigger_time && millis() > trigger_time - 15000) {
+		tone(SPEAKER_PIN, 440);
+	}
+	else if (trigger_time) {
+		tone(SPEAKER_PIN, 449);
+	} else {
+		noTone(SPEAKER_PIN);
+	}
+}
+
+void callback_game_start() {
+
+}
+
+void callback_game_stop() {
+
+}
diff --git a/src/template_module/main.ino b/src/template_module/main.ino
index 5d9baef..3b05aa5 100644
--- a/src/template_module/main.ino
+++ b/src/template_module/main.ino
@@ -4,7 +4,7 @@
 #include <obus_module.h>
 
 void setup() {
-	Serial.begin(9600);
+	Serial.begin(115200);
 
 	// Choose one
 	// Puzzle: a module that must be solved
@@ -13,7 +13,17 @@ void setup() {
 	// obus_module::setup(OBUS_TYPE_NEEDY, OBUS_NEEDY_ID_DEVELOPMENT);
 }
 
+obus_can::message message;
 
 void loop() {
-	obus_module::loop();
+	bool is_message_valid = obus_module::loop_puzzle(&message);
+	// bool bool is_message_valid = obus_module::loop_needy(&message);
+}
+
+void callback_game_start() {
+
+}
+
+void callback_game_stop() {
+
 }